Portable electronic devices must be capable of operating only upon power obtained from an internal electric battery. To keep the weight low, the batteries used in portable electronic devices must be small. Since small electric batteries can only provide limited amounts of power, portable electronic devices should be designed in manner such that power consumption is minimized.
Some existing portable electronic devices implement power management systems that reduce the amount of power consumed. For example, many portable computer systems contain power management systems that reduce the amount of power consumed by hard disk drive storage devices. The power management system monitors the use of the hard disk drive storage device. If the power management system determines that the hard disk drive has been inactive for a predetermined amount of time, the power management system parks the read/write head of the hard disk drive and spins down the physical hard disk.
Many portable electronic devices use some type of flat panel display system to display information to a user. For example, portable computers, portable televisions, and hand-held video games are constructed using a flat panel display system. Examples of flat panel display systems include active matrix liquid crystal displays, passive matrix liquid crystal displays, electroluminescent displays, field-emission cathode displays, gas-plasma displays, Light Emitting Diode (LED) displays, and Liquid Crystal displays (LCD).
The flat panel display system in a portable electronic device can draw significant amounts of power. It is therefore desirable to implement a power management system that reduces the amount of power consumed by the flat panel display system in a portable electronic device.